The clarity and precision of our written sentences are greatly dependent on how well we modify their various elements. Usually, of course, we modify nouns and pronouns with single adjective or adjective phrases (‚ÄúThe long wait is over.‚ÄĚ ‚ÄúIt was worth the trouble.‚ÄĚ) and verbs with single adverbs or adverb phrases (The day was exceedingly bright.‚ÄĚ ‚ÄúThe fugitive was summarily brought to justice.‚ÄĚ). Such grammatically simple modifications rarely leave room for doubt as to our intended meaning.

Every now and then, however, we need more complicated modifiers to convey precisely what we have in mind, as in this sentence: ‚ÄúGive me a real world example of a nation that was able to lift itself by its bootstraps.‚ÄĚ The problem is that while the noun phrase ‚Äúexample of a nation‚ÄĚ looks like it‚Äôs being modified by another noun phrase, ‚Äúreal world,‚ÄĚ the context is so difficult to pin down. Are we referring to a ‚Äúworld example of a nation‚ÄĚ that is real, which sounds nonsensical, or to an ‚Äúexample of a nation‚ÄĚ in the real world, which seems to make sense but only vaguely?

Thankfully, English has a handy grammatical tool for fixing problems caused by the unusual compounding of its words: the hyphen. When we use the hyphen to form the composite word ‚Äúreal-world,‚ÄĚ in particular, the semantic problem with the sentence we examined earlier simply vanishes: ‚ÄúGive me a real-world example of a nation that was able to lift itself by its bootstraps.‚ÄĚ This time, it‚Äôs clear that ‚Äúreal-world‚ÄĚ is meant to be a compound noun modifying the noun ‚Äúexample.‚ÄĚ

Hyphenation can help us achieve clarity in meaning in two major grammatical situations: (1) when we use nouns to modify adjectives, and (2) when we use phrases to modify nouns. There are some generally accepted rules for hyphenating such compound modifiers.

Hyphenating nouns used to modify adjectives. When we use a noun up front to modify an adjective, we need to put a hyphen between them for clarity: ‚ÄúThe insulin-dependent patient lived an otherwise normal life.‚ÄĚ ‚ÄúThe country promoted labor-intensive industries instead of capital-intensive ones.‚ÄĚ

Such noun-adjective modifiers, however, typically need to do away with the hyphen when they come after the noun they are meant to modify: ‚ÄúThe patient is no longer insulin dependent.‚ÄĚ ‚ÄúThe industries the country went into are not labor intensive.‚ÄĚ

Hyphenating phrases used to modify nouns. When a phrase is meant to modify a noun up front, we need to hyphenate the phrase for clarity: ‚ÄúThe big-budget film took five years to finish.‚ÄĚ ‚ÄúThe astute entrepreneur took advantage of the once-in-a-lifetime business opportunity.‚ÄĚ (See what happens when we knock off those hyphens.)

When adverb-adjective phrases are used to modify a noun up front, we need to hyphenate them if the adverb doesn‚Äôt end in ‚Äú-ly‚ÄĚ: ‚ÄúHer long-ailing husband made a dramatic recovery.‚ÄĚ ‚ÄúThe short-tempered boxer got knocked out early in the second round.‚ÄĚ But we should never do so when the adverb ends in ‚Äú-ly‚ÄĚ: ‚ÄúThe US dollar is the nearest we have to a globally accepted currency.‚ÄĚ ‚ÄúA hastily organized press conference was called by the beleaguered senatorial candidate.‚ÄĚ

When one of the adjectives in a two-adjective modifying phrase is meant to modify the other, we need to place a hyphen between them for clarity: ‚ÄúThe man lost his light-red jacket in the mall.‚ÄĚ When both adjectives modify the same noun, however, we need to skip the hyphen: ‚ÄúThe man lost his light red jacket in the mall.‚ÄĚ (Figure that one out.)

Using the suspensive hyphen. To streamline sentences, we can use the so-called suspensive hyphen for a series of two or more hyphenated compound modifiers with the same base element: ‚ÄúSmall- and medium-scale industries deserve government subsidy.‚ÄĚ ‚ÄúWe need five-, six-, and nine-meter poles for this project.‚ÄĚ Here, the words ‚Äúscale‚ÄĚ and ‚Äúmeter‚ÄĚ are base elements of the modifiers that are used only once for conciseness.

With these guidelines, we should now be able to correctly hyphenate our compound modifiers for clarity. (2007)